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Articles 1 - 10 of 10
Full-Text Articles in Physical Sciences and Mathematics
An Efficient Algorithm To Determine The Periodic Steady-State Solutions Of Nonlinear Systems Using Extended Spectral Analysis, Gülay Tohumoğlu
An Efficient Algorithm To Determine The Periodic Steady-State Solutions Of Nonlinear Systems Using Extended Spectral Analysis, Gülay Tohumoğlu
Turkish Journal of Electrical Engineering and Computer Sciences
A new method for the solution of nonlinear periodic systems was developed. It avoids the time domain calculations of the whole network equations. In the proposed method, by forming the augmented network as linear and nonlinear subnetworks these subnetworks are formulated in complex frequency and time domain respectively. Using spectral analysis the steady-state periodic solution of the whole nonlinear network is reached by an iterative approach. The method can be applied efficiently to weak and strong nonlinear circuits equally well. When we divide the network into a large linear subnetwork and a small nonlinear subnetwork, this method can be applied …
Radiation From An Impedance Loaded Parallel-Plate Waveguide, Fi̇li̇z Bi̇rbi̇r, Ali̇nur Büyükaksoy
Radiation From An Impedance Loaded Parallel-Plate Waveguide, Fi̇li̇z Bi̇rbi̇r, Ali̇nur Büyükaksoy
Turkish Journal of Electrical Engineering and Computer Sciences
A hybrid method consisting of employing the mode matching method in conjunction with the Fourier transform technique is used to analyze the radiation of the dominant TEM-wave from an impedance loaded parallel-plate waveguide. The hybrid method that we adopt here reduces the related boundary value problem to a scalar modified Wiener-Hopf equation of the second kind. The solution involves infinitely many unknown constants satisfying an infinite system of linear algebraic equations susceptible to a numerical treatment. Some computational results illustrating the effects of various parameters on the radiation phenomenon are also presented.
A Pseudo Spot Price Algorithm Applied To The Pumped-Storage Hydraulic Unit Scheduling Problem, Sali̇h Fadil, Celal Yaşar
A Pseudo Spot Price Algorithm Applied To The Pumped-Storage Hydraulic Unit Scheduling Problem, Sali̇h Fadil, Celal Yaşar
Turkish Journal of Electrical Engineering and Computer Sciences
A lossy electric power system that contains thermal units and a pumped-storage hydraulic unit is considered in this paper. The total cost of thermal units in an operation cycle is minimized under some possible electric and hydraulic constraints of the units. The operation cycle is divided into time intervals where the system loads are assumed to remain constant. The proposed solution technique has two main parts. In the first part, the active thermal generations and active generation or pumping power of the pumped-storage unit in all time intervals are determined by using units' active generation incremental costs and pseudo spot …
A Fuzzy Identification Method For Nonlinear Systems, İbrahi̇m Eksi̇n, Osman Kaan Erol
A Fuzzy Identification Method For Nonlinear Systems, İbrahi̇m Eksi̇n, Osman Kaan Erol
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, two mathematical ways of building a fuzzy model of both linear and nonlinear systems are presented and compared. In order to determine a model for a nonlinear system, the phase plane is divided into sub-regions and a linear model is assigned for each of these regions. This linear model is represented either in state-space or ARX model form. To determine the pre-selected parameters of the linear system model under study, least-square identification method is used. Then these linear models are arranged in a fuzzy manner to characterize the overall system behavior. The results show that this method …
Comparison Of Simulation Algorithms For The Hopfield Neural Network: An Application Of Economic Dispatch, Tankut Yalçinöz, Hali̇s Altun
Comparison Of Simulation Algorithms For The Hopfield Neural Network: An Application Of Economic Dispatch, Tankut Yalçinöz, Hali̇s Altun
Turkish Journal of Electrical Engineering and Computer Sciences
This paper is mainly concerned with an investigation of the suitability of Hopfield neural network structures in solving the power economic dispatch problem. For Hopfield neural network applications to this problem three important questions have been answered: what the size of the power system is; how efficient the computational method; and how to handle constraints. A new mapping process is formulated and a computational method for obtaining the weights and biases is described. A few simulation algorithms used to solve the dynamic equation of the Hopfield neural network are discussed. The results are compared with those of a classical technique, …
Distance Spectra For Trellis Coded Modulation Schemes On Channels With Intersymbol Interference, Sabi̇re Haciömeroğlu, Melek D. Yücel
Distance Spectra For Trellis Coded Modulation Schemes On Channels With Intersymbol Interference, Sabi̇re Haciömeroğlu, Melek D. Yücel
Turkish Journal of Electrical Engineering and Computer Sciences
The effect of intersymbol interference on distance spectra for trellis coded 8-PSK, 16-QAM and 32-AMPM modulation schemes is evaluated using the methods proposed by Schlegel. Distance spectra of 16-state 8-PSK scheme are computed for different intersymbol interference channels. It is seen that on channels with intersymbol interference the spectral lines are spread into a nearly continuous spectrum and the minimum Euclidean distance between codewords decreases severely. Hence, although the main contribution at large signal to noise ratios comes from the minimum Euclidean distance ( d_{free} ) , higher spectral components also become very important at moderate values of the signal …
Knowledge-Based Navigation For Autonomous Road Vehicles, Murat Eki̇nci̇, Franches W.J.Gibbs, Barry T. Thomas
Knowledge-Based Navigation For Autonomous Road Vehicles, Murat Eki̇nci̇, Franches W.J.Gibbs, Barry T. Thomas
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents a computer vision system for an autonomous road vehicle (ARV) that is capable of negotiating complex road networks including road junctions in real time. The ultimate aim of the system is to enable the vehicle to drive automatically along a given complex road network whose geometric description is known. This computer vision system includes three main techniques which are necessary for an ARV: a) road following, b) road junction detection, c) manoeuvring at the road junction. The road following algorithm presents a method of executing a number of algorithms using different methods concurrently, fusing their outputs together …
Decentralised H_{\Infty} Load Frequency Controller Design Based On Ssvs, Hasan Çi̇men
Decentralised H_{\Infty} Load Frequency Controller Design Based On Ssvs, Hasan Çi̇men
Turkish Journal of Electrical Engineering and Computer Sciences
The decentralised load-frequency controller design problem concerned is translated into an equivalent problem of decentralised controller design for a multi-area multi-input multi-output (MIMO) control system. It is shown that subject to a condition based on the structured singular values (SSVs), each local area load-frequency controller can be designed independently. The stability condition for the overall system can be stated as to achieve a sufficient interaction margin. It is demonstrated by computer simulation that within this general framework, local H$_{\infty}$ controllers can be designed to achieve satisfactory performances for a sample two-area power system.
Information And Average Information Rates Of A Graphical Access Structure On Six Vertices, Mustafa Atici
Information And Average Information Rates Of A Graphical Access Structure On Six Vertices, Mustafa Atici
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper we study the optimal information and average information rates of secret sharing schemes which are all connected graphs on six vertices. There are $102$ connected graphs on six vertices that are not complete multipartite graphs. Of these $102$ graphs, we determined the optimal information rate of $71$ graphs, and the optimal average information rate of $88$ graphs.
Control Chart Pattern Recognition Using Artificial Neural Networks, Şeref Sağiroğlu, Erkan Beşdok, Mehmet Erler
Control Chart Pattern Recognition Using Artificial Neural Networks, Şeref Sağiroğlu, Erkan Beşdok, Mehmet Erler
Turkish Journal of Electrical Engineering and Computer Sciences
Precise and fast control chart pattern (CCP) recognition is important for monitoring process environments to achieve appropriate control and to produce high quality products. CCPs can exhibit six types of pattern: normal, cyclic, increasing trend, decreasing trend, upward shift and downward shift. Except for normal patterns, all other patterns indicate that the process being monitored is not functioning correctly and requires adjustment. This paper describes a new type of neural network for speeding up the training process and to compare three training algorithms in terms of speed, performance and parameter complexity for CCP recognition. The networks are multilayered perceptrons trained …